Steam-engine valve



(No Model.)

W. D. HAVEN.

STEAM ENGINE VALVE.

No. 415,385. Patented Nov. 19. 1889.

$117 .GQZW W f i liu @03566: J www UNITED STATES PATENT OFFICE.

VILSON D. HAVEN, OF TRENTON, NEIV JERSEY.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters Patent No. 415,385, dated November19, 1889.

Application filed October 29, 1888. Serial No. 289,426. (No model.)

To all whom, it may concern.:

Be it known that I, WILSON D. HAVEN, a citizen of the United States,residing at Trenton, in the county of Mercer and State of New Jersey,have invented certain new and useful Improvements in Steam-En gineValves; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appert-ains to make and use the same.

My invention is directed to securing a greater accuracy of travel andgreater durability in steam-engine valves; and to this end it consistsin certain parts and combinations of parts hereinafter more particularlyset forth.

My invention relates to a construction of supporting and guiding devicesof the valvestem by which the valve is more accurately balanced, itsbearing equalized, and vibration of the valve-stem and valve prevented.

My invention also relates to aconstruction of the valve-ports by whichthe weight of the valve is carried by the steam-pressure and relievedfrom the lower part of the valve-seat, thereby rendering the wear uponall parts of the circumference of the valve and case equal.

In order to make my invention more clearly understood, I have shown inthe accompany-` ing drawings means for carrying the same into effect.

In said drawings, Figure l is a side view, partly in section, of so muchof a steam-engine as is necessary to illustrate my'invention. Fig. 2 isa longitudinal section on a larger scale of a simple form of theoutboardbearing for the valve stem. Fig. 3 is a crosssection on line 3 3of Eig. 2. Fig. 4 is a crosssection on line 4 Je of Fig. l.

Referring to the drawings, A indicates the steam-engine cylinder; B, thevalve-gear; C, the valve-stem; l), the valve-case or steamchest intowhich the live steam enters, asindicated by the arrows, and E the valveor valves mounted therein and secured to and actuated by the valve-stemC.

In the construction illustrated the valves are both oscillating andreciprocating; but such combined movements are not essential toobtaining all of the advantages of my '1nvention. The reciprocation ofthe valve regulates the exhaust by way of passages e, while theoscillation of the valve admits and cuts otf the steam in a well-knownmanner. Where the steam-admission ports of the valve are in the form oflong slits or openings, I have found that an unequal wear and chatteringof the valve in its seat takes place, due to the slight expansion of thehollow shell of the valve and the forcing out of the edges of the portsso made. I have obviated this diiiiculty to a considerable extent byforming the ports, as shown at a, with one or more cross-bridges a',adapted to maintain the proper cylindrical shape of the valve, preventthe forcing outward of the edges of the port, aud unequal wear andchattering in the valve-seat, resulting finally in a materially greaterdurability of these part-s.

At the end of the valve-case next to the valve-gear there is formed theusual stuiiingbox d for the passage of the valve-stem from the interiorof said case to the valve-gear, which box forms a guide and support forone end of the stem and valve.

I have discovered by practical experiment that the peculiar movements ofthe valve and stem incident to the use of the special valvegear shownhave a very objectionable and serious effect in cutting away the valve,steun and casing. I have, however, been able to obviate these seriousresults by combining with said valve-gearing what may be termed anoutboard-bearing, which I will now describe, lirst referring, however,more partielllarly to the valve-gear above mentioned. This gear was rstdescribed in Letters Patent No. 339,814, granted April I3, 1886, to F.Schumann and myself. It comprises, essentially, a rock-lever orequivalent moving part E, connected with the valve-stem forreciprocating it, a bell-crank lever G4, mounted upon a pivot g, carriedby said part E4, a means-such as a governor-rod IIL-for oscillating thebellcrank lever relative to part E, and connections-such as the rod J4and arm D4-between the other end of the bell-crank lever andthevalve-stem for oscillating the latter and the valve. 'lhis mechanismcauses a screw-like movement of the valve, which is, however, unequal,being rapid or accelerated IOO at one point, resulting in a seriousdeterioration of the valve and case. This I have obviated, as abovestated, by combining with said valve-gear and valve the followingguiding and supporting means.4

Referring more particularly to Figs. 2 and 3, G indicates the head ofthe valve-case, de-

tachably secured in any suitable manner, as by the hooked bolts g. Thishead is provided with a cylindrical sleeve G', extending in a directionor directions parallel with the valvestem. g g' indicate a two-partbushing mounted in the sleeve G', and of such interior diameter as toproperly tit the exterior Vof the valve-stem. The lateral edges of thetwo parts of the bushing do not touch, but are arranged to leave spaces,as shown in Fig. 3, to perinitot the lower halt' of the bushing-beingfrom time to time adjusted upward to compensate for the wear which takesplace between said lower half and the stem. This adjustment is providedfor by the screws g2, which are tapped into the under side of the sleeveG' and bear against the lower half of the bushing g. g3 is a ringfitting in the inner end of thesleeve G', and having between it and saidbushing a space g4 for the reception of a suitable packing. The sleeveand bushing above described are of such length as to permit thenecessary reciprocation of the valve-stem, and as a finish and to shutout from view the moving end of said stem I provide the outer end of thebearing with a cap G2, which is adapted to be secured upon the sleeve G.

The bearing above described serves to balance the valve-stem by exposingto the outer air at this end of the valve-case an area equal to that ofthe cross-section of the valve-stem at the end next the valve-gear. Tothis end the cap G2 is provided with an opening g4, through whichatmospheric pressure acts upon the end of the stem.

In order to further take off wear from the under side of the valve andstem, I have constructed the upper port or ports of the oscillatingvalve-shell of a slightly less area than that of the lower port orports. Referring to Fig. 4, it will be seen that of the four steamportsd shown in the construction there illus trated those at the upper sideofthe valve are the smaller. As this difference is in practice of smallaccount, I have indicated the larger ports by the letters 'y y and thesmaller ports by the letters 5c. The difference in area will beproportionate to the weight of thevalve and to the steam-pressure underwhich the engine is constructed and adjusted to run, and will of coursevary in different engines. The result of this construction is that theweight of the valve and stem may be entirely sustained by the live-steampressure and the friction and wear between the moving and stationaryparts much diminished.

I-laving thus described my invention, what I claim is '1. In an engine,the combination, with the valve, valve-stem, and casing, of a movingpartsuch as lever Ei-for reciprocating the valve, a bell-crank levermounted upon a pivot carried by said part, means for oscillating thebell-crank lever relative to said moving part, connections between thebell-crank lever and the valve for oscillating thelatter, and anoutboard-bearing situated at the end of the valve opposite saidvalve-gearing and supporting t-he valve-stem, substantially as setforth.

2. The combination, with the valve, the valve-stem, and the valvecasingprovided with the stuffing-box and bearing d, of the outboard-bearingprovided with the bushing g', divided horizontally, as described, andadjusting devices for raising the lower half of said bushing,substantially as set forth.-

3. The combination,` with the valve, the valvestem, and the valve-casinghaving the bearing d, of the outboard-bearing at the opposite end ot'said casing, consisting of a sleeve G', lianged and divided bushing g',and the cap G2, fitting and secured to the end of said sleeve andsecuring the flanges of said bushing between itself and Vsaid sleeve,substantially as set forth.

4. The combination, with the valve-casing having ports on its upper andunder sides, of the hollow valve provided with corresponding portsadapted to simultaneously open and *admit steam tothe cylinder throughboth the upper and under ports, the upper of said valveports being ofsmaller area than the lower, substantially as set forth.

In testimony whereof I aflix my signature in the presence of twowitnesses.

WILSON D. HAVEN. NVitnesseszl C. L. HARDING,

DAVIDT. IvINs'.

Ico

